How to Recover Hard Disk Space on a Mac with OmniDiskSweeper

Running out of disk space is no fun and Mac users with smaller drives need to be particularly aware of available disk space. The OS X Finder Search feature can be used to find large files but if you’re really serious about managing disk space and tracking down unnecessary large files and folders, you should use a free tool called OmniDiskSweeper.

OmniDiskSweeper is an excellent application for Mac OS X that shows everything on a hard disk in descending order by size, each directory can then be drilled down into further to quickly locate the largest files, and the offending folders or files can be deleted directly from the app. Finding the large files and folders with OmniDiskSweeper is quick and painless:

Let OmniDiskSweeper sweep the drive to find all files by size, then click on the topmost directories to find items that can be deleted

Important: OmniDiskSweeper is intended for users who are knowledgable about their Mac file system. If you don’t absolutely know what a file or directory is and if it’s necessary or not, do not delete it! There is no going back, and if you accidentally delete important system files or folders you may find yourself having to recover from a backup or reinstalling OS X. You’ve been warned.

Exactly what can be removed is going to vary per user and per drive, but everyone will certainly find items that are no longer necessary to keep around. For example, sweeping my drive with OmniDiskSweeper I discovered and removed the following items:

The user ~/Library/Application Support/ directory contained 1GB of files for apps that are no longer used

900MB of unused and long forgotten Applications were uninstalled freeing up space

Ultimately how much all this matters and how much disk space you need to reclaim is going to depend on the capacity of a Mac hard drive. I use a MacBook Air 11″ with only a 64GB SSD making each 1GB of unnecessary files or folders significant, and I was able to quickly recover about 12% of total disk capacity just by looking through OmniDiskSweeper and removing what I know isn’t needed.